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Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra
1 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. AuthorsNames
Segmento de Tierra
Ana Laverón Simavilla
E-USOC/Dpto. de Vehículos Aeroespaciales
ETSI de Aeronáuticos, UPM
2 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Contents
• Introduction
• Basic description of the Ground Segment
• Design considerations
– Coverage required per S/C
– Type of orbit/mission
– Number of S/Cs
– Number of P/Ls and data processing needs
– Manned or unmanned missions
– Number and location of Ground Stations
– Security issues
• Ground Segment requirements
• Cost reduction scenarios
3 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Contents
• Ground segment definition and functions
• High level architecture. Core elements
• Alternative architectures for different missions
• Ground segment phases
4 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
INTRODUCTION
5 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Space system
• Space segment
• Ground segment
– Infrastructure and systems needed to operate the space segment
– Link between the final users and the space segment
• Users segment
6 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Relevance of the Ground Segmet
• Importance of Ground Segment in Satellite Communications – Until not long ago, satellites were based on a relatively simple
architecture, i.e., the bent-pipe design
– The introduction of some satellite constellations and on-board processing started to become really complicated for the satellite industry
• Some architectures have very complex Space Segment
• Some architectures adopted simpler Space Segment and more complex Ground Segment
– According to ESA
• 80% of the satellite communications market is in the ground segment - sale of satellite terminal equipment and provision of value-added services
• 20% space segment itself - satellite production, launch and operations
– The satellite and space industry lives in a contradiction: while people’s attention is often focused on the space segment, it is the ground segment that does a lot of the work that adds value to satellite communications
8 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Relevance of the Ground Segment
Ground Space
Requirements
Functionality Real-time embedded
Interoperability P/L specific
Autonomy Reuse bus
Architecture
Distributed network Processor constrained
Integration
More COTS Standard bus interfaces
More external interfaces
Team
Dispersed 1 or 2 teams
Different processes
Code size
2.0-4.0 M SLOC 0.01-0.5 M SLOC
• Criticality of SW design
Ground Software
is Highest Risk!!!
9 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
BASIC DESCRIPTION OF THE
GROUND SEGMENT
10 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Space system main blocks
Space
segmentEnd users
Ground segment
Data
managementTM/TC
TM/TC
Users data
Operations support
Spacecraft operations
Payload operations
Mission operations
Ground
StationTM/TC
11 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Ground Segment main elements
• Ground Stations
– Tracking
– Reception of TM (HR & LR from P/L & S/C)
– Uplink of TC (P/L & S/C)
• Control Centers
– Mission Control
– P/L Operations
– S/C Operations
– Coordination of Ground Stations
– Data archiving
– Data processing
• Final users
– Telecommunication users
– Scientists
– …
12 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Data management paths
Space
segmentEnd users
Ground segment
Data Relay
Operations support Requests
Mission data Mission data
Command &
Tracking data
Mission data
H&S TM
13 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
DESIGN CONSIDERATIONS
14 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Design considerations
• Coverage required per S/C
• Type of orbit/mission
• Number of S/Cs
• Number of P/Ls and data processing needs
• Manned or unmanned mission
• Number and location of Ground Stations
• Security issues
15 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Design considerations
• Coverage required per S/C
• Type of orbit/mission
• Number of S/Cs
• Number of P/Ls and data processing needs
• Manned or unmanned mission
• Number and location of Ground Stations
• Security issues
16 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Coverage required per S/C 1/6
• Coverage: frequency and amount of time per orbit that a S/C needs to be linked to the GS
– It depends on many factors
• Amount of data to be transferred
– TC and housekeeping TM is not an issue
– P/L data can be an issue
– Data rate of the downlink
• S/C Autonomy
– Lack of onboard command storage
– Requirement to receive mission data
• Manned missions
• Need of continuous access, e.g. telecommunications S/Cs
• Phase of the mission (e.g. LEOP)
– It can determine the number and location of the Ground Stations
17 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Coverage required per S/C 2/6
• Coverage study
– Circle of accessibility: it depends on the Ground Station (, minimum elevation) and the S/C (h, altitude)
18 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Coverage required per S/C 3/6
Coverage area from Torrejón and Maspalomas (=5º)
– Solid lines – INGENIO (Sun-synchronous, 667,78 km)
– Dashed lines – PAZ (Sun-synchronous, 510 km)
19 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Coverage required per S/C 4/6
– Passes over the station (e.g. EURECA daily passes)
• Number of consecutive passes
• Duration of the passes
20 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Coverage required per S/C 5/6
Three first orbits of ERS-1 ( i=98.5º, h=785 km) during the Launch and Early Orbit Phase (LEOP)
21 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Coverage required per S/C 6/6
• How can the coverage influence the Ground Station design or selection?
1. Determine the P/L data to be transfered (e.g. Biomass)
a) P/L data rate (e.g.: 102 Mbps )
b) Duty cycle (e.g.: 20%)
2. Select a Ground Station location (e.g. Svalbard, Norway for Biomass)
a) Study the coverage
i. Frequency of the passes
ii. Duration of each pass
3. From 1. and 2. determine the downlink data rate needed (e.g. 100-250 Mb/s)
4. Does the selected Ground Station meet the requirement?
22 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Design considerations
• Coverage required per S/C
• Type of orbit/mission
• Number of S/Cs
• Number of P/Ls and data processing needs
• Manned or unmanned mission
• Number and location of Ground Stations
• Security issues
23 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Type of orbit/mission 1/6
• Each type of orbit/mission can make use of different communication links, each type of link require different Ground Station setups – LEO, MEO
Store and forward link
Crosslink in communication satellite systems
Make use of available communication services Air Force Satellite Control Network (AFSCN)
NASA Tracking and Data Relay Satellite System (TDRSS)
– Molniya
– GEO
Store and forward link
Ground Station relays
Crosslink in communication satellite systems
24 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Type of orbit/mission 2/6
– Space Science missions
Store and forward link
Make use of available communication services
ESA Tracking Stations Network (ESTRACK)
NASA Deep Space Network (DSN)
25 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Type of orbit/mission 3/6
• LEO with store and forward link
– High transmission delay for communications with 1 S/C (Starsys)
– Constellations with many gateways (Globalstar)
– Reduced transmitter power due to low altitude
– If the data amount is high
• Many Ground Stations
• Very high data rates
26 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Type of orbit/mission 4/6
• LEO with crosslink
– Used in communication satellite systems
– Large coverage area
– Possibility of polar coverage
– Highly survivable due to mutiple paths
– Reduced jamming susceptibility due to limited Earth view area
– Reduced transmitter power due to low altitude
27 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Type of orbit/mission 5/6
• GEO with GS relay
• No need to switch between satellites
• No need of antenna tracking
• High-cost launch
• High-cost satellite
• High-coverage
• No polar regions coverage
28 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Type of orbit/mission 6/6
• Molniya orbit
– Coverage in high latitudes
– Low-cost launch
– Complex network control
– Need for GS antenna pointing
– Need for S/C handover
29 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Design considerations
• Coverage required per S/C
• Type of orbit/mission
• Number of S/Cs
• Number of P/Ls and data processing needs
• Manned or unmanned mission
• Number and location of Ground Stations
• Security issues
30 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Number of S/Cs
• Overlaps of S/Cs at the same Ground Station
• Gaps between S/Cs passes
– Should be enough to enable the change from one S/C to the other
• Complex operations
31 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Design considerations
• Coverage required per S/C
• Type of orbit/mission
• Number of S/Cs
• Number of P/Ls and data processing needs
• Manned or unmanned mission
• Number and location of Ground Stations
• Security issues
32 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Number of P/Ls and
data processing needs 1/3
• The data user’s requirements determine the complexity of the distribution systems
– Acceptable error rate
– Acceptable delay receiving the
• TM – “TM available in less than 3 hours after sensing” (impact on coverage requirement)
• processed TM in different levels – “Level 3 TM available in less than 5 hours after sensing” (impact on data handling and P/L CC)
• Number of final users
• Location of the final users
33 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Number of P/Ls and
data processing needs 2/3
• If the S/C has several instruments each user will probably need – all the data from one of the P/Ls
– a small portion from the other P/Ls
– a portion of housekeeping TM
– a portion of Flight Dynamics TM
• Different users will need data processed in different Levels
• The data processing for higher levels require the knowledge and cooperation of scientists
34 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Number of P/Ls and
data processing needs 3/3
• Committee on Data Management, Archiving and Computing (CODMAC) Data Level Definitions
– Level 0: reconstructed, unprocessed instrument/payload data at full resolution; raw engineering measurements (any and all communications artifacts, e.g. synchronization frames, communications headers, duplicate data removed)
– Level 1: reconstructed, unprocessed instrument data at full resolution, time-referenced, and annotated with ancillary information, including radiometric and geometric calibration coefficients and georeferencing parameters, e.g., platform ephemeric, computed and appended but not applied to the Level 0 data
– Level 2: derived geophysical variables at the same resolution and location as the Level 1 source data
– Level 3: variables mapped on uniform space-time grid scales, usually with some completeness and consistency
– Level 4: model output or results from analyses of lower level data (i.e., variables derived from multiple measurements)
• Some others – Raw TM: as downlinked from the S/C
– Level 1B: Level 1 data processed to sensor units
37 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Design considerations
• Coverage required per S/C
• Type of orbit/mission
• Number of S/Cs
• Number of P/Ls and data processing needs
• Manned or unmanned mission
• Number and location of Ground Stations
• Security issues
38 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Manned or unmanned mission
• Security requirements
• Safety requirements
• Safe return of astronauts
• 24x7 Ops coverage vs. Automated Ops
39 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Design considerations
• Coverage required per S/C
• Type of orbit/mission
• Number of S/Cs
• Number of P/Ls and data processing needs
• Manned or unmanned mission
• Number and location of Ground Stations
• Security issues
40 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Number and location
of Ground Stations
• Existing or new
• Dedicated or shared
• Fixed or mobile
41 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Design considerations
• Coverage required per S/C
• Type of orbit/mission
• Number of S/Cs
• Number of P/Ls and data processing needs
• Manned or unmanned mission
• Number and location of Ground Stations
• Security issues
42 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Security issues
• End-to-end lines
• Use of the www
43 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
GROUND SEGMENT
REQUIREMENTS
44 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Ground segment requirements 1/2
• Ground segment requisites
– Support the operations, data processing and handling with
• High reliability
• High availability
• High fidelity
• High flexibility
• High security
– Cost reasons will reduce some/all of the above characteristics of the GS
• Cost considerations
– Operations 30-40% of the overall programme
45 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Ground segment requirements 2/2
• Type of requirements
– No loss of data
• No missing passes
• No missing data
– Fast return of critical data
– Regular return of bulk data
– Rapid response for critical commanding
– Ease of access to data
– Data management security
• Compromises to reduce redundacies and cost
– Acceptance of small loss of passes (1 in 1000)
– Acceptance of small loss of data (<1%)
– No rapid return of non-urgent data (data available <3 hours after sensing)
46 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
COST REDUCTION SCENARIOS
47 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Cost reduction scenarios 1/3
• Reliability
– Some small passes loss and data loss should be accepted as they should not risk the mission, and enable important cost reduccions in redundant HW, SW and operations costs
– This is not applicable to manned missions
• Data availability
– Real-time and near real time data is expensive, and should be reduced to the critical phases of the mission
• Commisioning
• Troubleshooting…
– Processing and transferring the data in very short times is also very expensive by means of human resources (24x7) and communication links (bandwidths)
48 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Cost reduction scenarios 2/3
• Data management security
– Security policies are also very expensive and its need should be evaluated carefully
• Dedicated communication links
• Operation support tools in secure networks
• SW development
– Increasing the ammount of COTS SW should reduce the development costs
– Reuse of SW from previous similar missions should also be increased
49 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Cost reduction scenarios 3/3
• Increase autonomy of operations to reduce manpower costs
– Tracking
– Automatic retuning of the frequency set-up
– Automatic reception and storage of downlinked TM
– Automatic conversion of critical raw data to engineering units
– Automatic checking of critical data
– Automatic dialing to on-call engineers
– Automatic distribution of data to end users
– Automatic production of summary TM quality
– Uplink of automated procedures
50 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
GROUND SEGMENT DEFINITION
AND FUNCTIONS
51 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Ground segment
Definition
ECSS-E-70 all ground facilities and personnel involved in the preparation or execution of mission operations
52 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Mission operations
Comprise the subset of mission engineering activities identifiable for:
– flight operations
– ground operations
– logistics engineering
required to operate the space segment.
53 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Ground segment composition
Space
Segment
Element
Element
Element
Ground Segment
Ground Operations
Organization
Ground Systems
En
tity
A Element
Element
Organization A
Element
Element
Facility A
Element
Element
Organization B
Element
Element
Facility B
En
tity
B
Space
Operations
Organization
Element
Element
Element
Ground Segment Domain
54 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Mission operations and mission success
• Ground systems and operations are key elements of a space system and as such play an essential
role in achieving mission success.
• Mission success is defined as the achievement of the target mission objectives as expressed in terms
of the quantity, quality and availability of delivered mission products and services within a given
cost envelope.
• Mission success requires successful completion of a long and complex process covering the
definition, design, implementation, validation, in flight operations and post operational activities,
involving both the ground segment and also space segment elements.
• It involves technical activities, as well as human and financial resources, and encompasses the full
range of space engineering disciplines. Moreover it necessitates a close link between the design of
the ground segment and the space segment in order to ensure proper compatibility between both
elements of the complete space system.
55 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Ground systems
Definition
ECSS-E-70 All ground infrastructure elements that are used to support the preparation activities leading up to mission operations, the
conduct of mission operations and all post-operational activities
56 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Functions of the Ground Segment
• Maintain RF communications links
• Provide S/C control to ground operators
• Process and archive telemetry (Tracking, Health & Safety)
• Provide P/L control to ground operators
• Process and archive telemetry (P/L data)
• Support Mission Operations
• Provide P/L data to the end users
• Provide communications between CCs
57 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Functions of the Ground Segment
• Provide S/C control to ground operators
– Number of S/C and orbital configurations
– Tracking methods
• Range and range rate
• Antenna viewing angles
• External tracking network
• Spacecraft autonomy
• Provide P/L control to ground operators
– Number of P/Ls
– Number and location of P/L control centers
58 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Functions of the Ground Segment
• Process and archive telemetry (P/L data)
– Number and location of expert centers
– Amount of data generated by the P/Ls
– Delay between data acquisition and data submittal to users
– Processing complexity
• On board
• On ground
59 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Functions of the Ground Segment
• Provide P/L data to the end users
– Number and location of users
– Amount of data to be delivered to the users
– Direct link or processed data
• Communications between CCs
– TM
– TC
– Voice
– Video
60 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
HIGH LEVEL ARCHITECTURE.
CORE ELEMENTS
61 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Ground system elements
• The facilities point of view
• The data flow point of view
• The SW elements point of view
• The functional point of view
• …
62 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Ground system elements
STC
EGOS
ESA Ground Operations Software System
MPS
63 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Space
Segment
Platform
Payload
Ground Segment
Mission
Control
System
(MCS)
Ground
Station
System
(GSTS)
Ground
Communications
Subnet (GCS)
Electrical Ground
Support
Equipment
(EGSE)
Space
subnet
link
Space
subnet
link
Assembly
integration
and test subnet
AIT subnet
Space &
Ground
Simulation
System (SGSS)
GC
S
GCS
Mission
Exploitation
System
(MES)
GCS
1. Mission control system (MCS)
2. Mission exploitation system (MES)
3. Ground station system (GSTS)
4. Ground communication subnet (GCS)
5. Space & Ground simulation system (SGSS)
6. Electrical ground support equipment (EGSE)
Ground system elements
64 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Space
Segment
Platform
Payload
Ground Segment
Mission
Control
System
(MCS)
Ground
Station
System
(GSTS)
Ground
Communications
Subnet (GCS)
Electrical Ground
Support
Equipment
(EGSE)
Space
subnet
link
Space
subnet
link
Assembly
integration
and test subnet
AIT subnet
Space &
Ground
Simulation
System (SGSS)
GC
S
GCS
Mission
Exploitation
System
(MES)
GCS
Ground system elements
1. Mission control system (MCS)
2. Mission exploitation system (MES)
3. Ground station system (GSTS)
4. Ground communication subnet (GCS)
5. Space & Ground simulation system (SGSS)
6. Electrical ground support equipment (EGSE)
65 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Mission control system (MCS)
Elements required to control the mission and to exploit the products, which are:
- Operations control system (OCS)
a. Flight dynamics (FDS)
- Payload control system (PCS)
- Data distribution
- Data base
- Mission exploitation system (MES)
66 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Mission control system (MCS)
Operations control system
(OCS) supporting
a. Flight operations
b. Ground operations
c. Mission control
d. Analysis of performance of
the mission
e. Analysis of the performance
of the system
f. Control over the system
configuration
67 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Mission control system (MCS)
Flight dynamics system (FDS)
a. Prediction of orbital elements
b. Attitude determination
c. Manoeuvres planning and
specification of all the
operational stages
- LEOP
- DRIFT
- Commissioning
- Nominal operations
d. Prediction of antenna
visibility
e. Acquisition and processing of
external geophysical and
dynamical data
f. Prediction of relevant
operational events
68 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Mission control system (MCS)
Payload control system (PCS)
supporting
a. Planning of the payload
elements
b. Monitoring and control of
the payload elements
c. Performance evaluation of
the payload elements
69 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Ground system elements
Nav
igat
ion
elem
ents
Ant
enna
poi
ntin
g co
mm
ands
TC
history
TC
results
Navigation requests
TM
Tra
ckin
g da
taTC
schedule
Space link schedule
Flight schedules, updates & plans
OCS
FDS MPS
Relations between main MCS elements
70 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Mission control system (MCS)
Data distribution
- Repository of all the data
collected during the mission
lifetime
Mission data Base
- Definition of all the mission
data
71 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Data distribution system (DDS)
• Instrument data processing for 3 instruments
Decrypter
Mission Data
1 Mbps
Instrument
Data
Deconmutator
1 Mbps
Instrument A
Data Buffer &
Deconmutator
Instrument B
Data Buffer &
Deconmutator
Instrument B
Data Buffer &
Deconmutator
User A
Conmutator
User A
Conmutator
User A
Conmutator
Recorder
Recorder
Recorder
500 kbps
700 kbps
1 Mpbs
10
kbps
8
kbps
12
kbps
520 kbps
722 kbps
1018 kpbs
520 kbps
722 kbps
1018 kpbs
72 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Data distribution system (DDS)
• Data processing
Ground Segment
P/L CC
DecrypterSC Data
Instrument
Data
Deconmutator
1 Mbps
Instrument A
Data Buffer,
Deconmutator
& Processing
Instrument A
Data for other
instruments
Instrument A
Data Buffer,
Conmutator &
Processing
Other
Instruments
Data
Data for
Other
Instruments
MCC
FOCC
FO Data
HK Data
FO Data
Deconmutator for
Instrument A, Data
Buffer, & Processing
HK Data
Deconmutator for
Instrument A, Data
Buffer, & Processing
Instrument A
Expert Center
Instrument A
Data Buffer,
Conmutator &
Processing
Calibration/
Data
Users
community
Requests/
Processed
Data
73 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Space
Segment
Platform
Payload
Ground Segment
Mission
Control
System
(MCS)
Ground
Station
System
(GSTS)
Ground
Communications
Subnet (GCS)
Electrical Ground
Support
Equipment
(EGSE)
Space
subnet
link
Space
subnet
link
Assembly
integration
and test subnet
AIT subnet
Space &
Ground
Simulation
System (SGSS)
GC
S
GCS
Mission
Exploitation
System
(MES)
GCS
Ground system elements
1. Mission control system (MCS)
2. Mission exploitation system (MES)
3. Ground station system (GSTS)
4. Ground communication subnet (GCS)
5. Space & Ground simulation system (SGSS)
6. Electrical ground support equipment (EGSE)
74 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Provide users with mission products
- Raw data (images, TM)
- Rectified data (geometrically and radiometrically) using satellite housekeeping TM and other PL housekeeping TM
Long term archive, for generation of products and for dissemination to users
Statistic about the quality of the data, and reports of the mission performance
Supporting the users establishing high level production plan
Mission exploitation system (MES)
75 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Space
Segment
Platform
Payload
Ground Segment
Mission
Control
System
(MCS)
Ground
Station
System
(GSTS)
Ground
Communications
Subnet (GCS)
Electrical Ground
Support
Equipment
(EGSE)
Space
subnet
link
Space
subnet
link
Assembly
integration
and test subnet
AIT subnet
Space &
Ground
Simulation
System (SGSS)
GC
S
GCS
Mission
Exploitation
System
(MES)
GCS
Ground system elements
1. Mission control system (MCS)
2. Mission exploitation system (MES)
3. Ground station system (GSTS)
4. Ground communication subnet (GCS)
5. Space & Ground simulation system (SGSS)
6. Electrical ground support equipment (EGSE)
76 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Ground Station system (GSTS)
It is the direct interface with the space segment while in orbit, and with the MCS.
It provides support functions for controlling the space segment elements and exploiting the mission products
Logical instances:
a. GSTS-SSC: in support of space segment control for the platform and payload
b. GSTS-ME: in support of mission exploitation
77 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Ground station system (GSTS)
− RF chains (uplink/downlink) dealing with the transmission/reception of signal to/from the space segment
− Baseband units performing modulation/demodulation of the signals to/from the space segment
− RF and baseband units performing the tracking
Antenna
RF Equipment
TM/TC Processors
Station M & C
Ground Station
78 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Ground station system (GSTS)
• Routine navigation of a spacecraft around the Solar System relies on two tracking methods: ranging and two-way Doppler
- Precisely measuring the time it takes radio signals to travel to and from a spacecraft gives the distance from the ground station;‘two-way range’. (Random errors down to 1 m)
- measuring the signal’s Doppler shift provides the craft’s velocity along that line-of-sight; ‘range-rate’. (Random errors down to 0,1 mm/s)
79 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Ground station system (GSTS)
• The other two position coordinates, against the sky background, are obtained only indirectly from the motion of the ground station as the Earth rotates
• The craft’s velocity components in the plane-of-sky are not measured and can only be found from how the position changes from day to day
80 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Ground station system (GSTS)
• Angular spacecraft positioning can be measured using two widely separated antennas to simultaneously track a transmitting probe: Differential One-way Range (DOR)
– Delta-DOR corrects errors “tracking” a quasar in a direction close to the spacecraft for calibration. (Errors down to 500 billionths of a degree/nanoradian)
81 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Ground station system (GSTS)
− Processing elements to perform the handling of the data sent by the MCS that has to be transmitted to the space segment
− Processors dealing with the formating of the data structures (packets) to be transmited to the MCS
− Processors/processes dealing with the monitoring and control of the network elements
− Calibration units to verify the station performances
− Test units
Antenna
RF Equipment
TM/TC Processors
Station M & C
Ground Station
82 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Ground station system (GSTS)
− From the reception stand-point
a. Conditioning
b. Filtering
c. Sychronisation
d. Demultiplexing
e. Packetization
of the downlinked data
− From the transmition point of view
a. Check data streams generated within the GS
b. Modulate the signals
c. Amplify the signals
Antenna
RF Equipment
TM/TC Processors
Station M & C
Ground Station
83 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Space
Segment
Platform
Payload
Ground Segment
Mission
Control
System
(MCS)
Ground
Station
System
(GSTS)
Ground
Communications
Subnet (GCS)
Electrical Ground
Support
Equipment
(EGSE)
Space
subnet
link
Space
subnet
link
Assembly
integration
and test subnet
AIT subnet
Space &
Ground
Simulation
System (SGSS)
GC
S
GCS
Mission
Exploitation
System
(MES)
GCS
Ground system elements
1. Mission control system (MCS)
2. Mission exploitation system (MES)
3. Ground station system (GSTS)
4. Ground communication subnet (GCS)
5. Space & Ground simulation system (SGSS)
6. Electrical ground support equipment (EGSE)
84 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Ground communications
subnetwork (GCS)
It connects all operational ground facilities.
a. Commnunications equipment to send/receive data
b. Communication lines and services
Other subnetworks are:
a. Space link subnet
b. AIT subnet
85 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Space
Segment
Platform
Payload
Ground Segment
Mission
Control
System
(MCS)
Ground
Station
System
(GSTS)
Ground
Communications
Subnet (GCS)
Electrical Ground
Support
Equipment
(EGSE)
Space
subnet
link
Space
subnet
link
Assembly
integration
and test subnet
AIT subnet
Space &
Ground
Simulation
System (SGSS)
GC
S
GCS
Mission
Exploitation
System
(MES)
GCS
Ground system elements
1. Mission control system (MCS)
2. Mission exploitation system (MES)
3. Electrical ground support equipment (EGSE)
4. Ground station system (GSTS)
5. Ground communication subnet (GCS)
6. Space & Ground simulation system (SGSS)
86 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Space and ground
simulation facility (SSF)
- It supports the validation of critical operational data
a. Databases
b. Procedures
- It supports training activities
SSF
Space
seg
men
t
mon
itorin
g
Ground segm
ent
monitoring
Ra
dio
me
ter
au
xili
ary
da
ta
Gro
und s
egm
net
com
mands
Space s
egm
net
com
mands
87 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Space
Segment
Platform
Payload
Ground Segment
Mission
Control
System
(MCS)
Ground
Station
System
(GSTS)
Ground
Communications
Subnet (GCS)
Electrical Ground
Support
Equipment
(EGSE)
Space
subnet
link
Space
subnet
link
Assembly
integration
and test subnet
AIT subnet
Space &
Ground
Simulation
System (SGSS)
GC
S
GCS
Mission
Exploitation
System
(MES)
GCS
Ground system elements
1. Mission control system (MCS)
2. Mission exploitation system (MES)
3. Ground station system (GSTS)
4. Ground communication subnet (GCS)
5. Space & Ground simulation system (SGSS)
6. Electrical ground support equipment (EGSE)
88 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Electric ground support
equipment (EGSE)
It is part of the overall ground support equipment (GSE), supporting the verification of the space segment during assembly, integration and test (AIT)
It supports operations in the use of the GMs
M&C
MDB
Simulator EGSE
89 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
ALTERNATIVE ARCHITECTURES
FOR DIFFERENT MISSIONS
90 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
• James Webb Telescope GS (launch 2013)
• MSG GS
– Facilities diagram
– Functional block diagram
• ISS GS
– Columbus GS
– ATV GS
• COTS GS
91 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
JWT GS
Madrid
Goldstone
Camberra
S b
and
- Commands
- Observations
- Observation plan
- FSW loads
- Ranging/tracking
- Contingency TM stream
X-b
and
- Recorder data
- Nominal TM stream
- Recorder data files
- TM stream
- Ranging/tracking - Commands
- Ranging/tracking
Jet Propulsion
Laboratory
(JPL)
- Cache recorder data
- Schedule DSN resources
Level 0 processing
of recorder data
Flight Dynamics
Facility (FDF)Ranging/tracking
Ephemerides
Science and Operations Center (SOC)
Flight Operations Center
(FOS)
Command & Telemetry
System (CTS)Recorder data files
TM
Commands
FSW loads
DSN schedule
Project Reference
Database
Management
System (PRD MS)
PR
D D
ata
Observatory
test-bed (OTB)
PRD Data
TM
Cmd
Proposal Planning
System (PPS)
Ephemerides
Observation
plans
Payload control
system
Data Management
System (DMS)
PL image
data
Recorder
Data
filesActuators
Cmds
PRD Data
Data
products
Proposals
Ep
he
me
rid
es
Flight SW
development labs
FS
W lo
ad
s
New development
JWT & NGST development
Other developtmens
92 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
MSG GS
• Facilities diagram
Communications backbone
EGSE LEOPBack-up and
Ranging Ground
Station
(BRGS)
Primary Ground
Station
(PGS)
Central Facility
(CF)
Back-up Satellite
control center
(BSCC)
Satellite M&C
- TM/TC
- Tracking
- Tracking
- TM/TC (back-up)
Space and
Ground Simulation
Facility
(SGSF)
Ground Segment M&C
Image Processing
Facility
(IMPF)
Data Acquisition
and Dissemination
Facility
(DADF)
Meteorological
Products
Extraction Facility
(MPEF)
Re
ctifie
d
ima
ge
s
Products
Rectified images
MSG Archive and
Retrieval Facility
(U-MARF)
Raw & rectified images
TM
Products
93 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
MSG GS
• Functional block diagram
TM TC
Rangin
g
Radiometer data stre
am
EGSELEOP
GS
Monitor
& Control
Space and
Ground Segment
Simulation
M&C
Operations
preparation
Image acquisition
and processing
S/C
Monitor
& Control
Mission Planning
& Scheduling
Metereological
product extraction
Archiving
&
Retrieval
End user support
center
Re
ctifie
d
da
ta
Ca
libra
tio
n
da
ta
Rectified &
raw data
Retrieval of data
Radiometer aux. data
Flight dynamics data
Sch
ed
ule
s
& a
ctiiv
itie
s
Simulation
data
Simulation
data
TC
TC & TMTM
Products
Re
trie
va
l
of p
rod
ucts
Retrieval
of products
Retrieval
of products
94 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
ATV GS
95 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Columbus GS
96 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
GROUND SEGMENT PHASES
97 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Ground segment phases 1/3
PHASE 0/A B
OBJECTIVE Mission analysis and feasibility Ground segment preliminary design
ACTIVITIES
REVIEWS GS Requirements Review GS Preliminary Design Review
INPUTS/OUTPUTS Mission RD Mission Ops Concept (D)
Customers RD (D) Space-to-Ground ICD (D)
EGSE Requirements from the SSC Customer RD
GS Baseline Definition
- Identify characteristics,
constraints, conceps.
- Assess feasibility (GS
perspective)
- Precise definition of the GSB to confirm
feasibility, prepare choice of suppliers,
start the implementation
- The GS is decomposed into its main
elements
GSRR GSPDR
System definition
98 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Ground segment phases 2/3
PHASE C D
OBJECTIVE
GS Detailed design GS Production and Validation
Production Integration and technical verification and validation
Operational validation
ACTIVITIES
REVIEWS
- GS Design to
element level
and start
implementation
-Definition of the
ops. Org. And
start of
production of
mission
operations data
Procure GS
facilities and
elements
GSCDR ORR
Ground Segment Implementation
Train personnel
Validate full GS
Includes
preliminary
validation of
mission data
Operations
99 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Ground segment phases 3/3
PHASE E F
OBJECTIVE
Operations execution Disposal
LEOP & commissioning Routine operations
ACTIVITIES
REVIEWS
Acquire mission
orbit/configuration
and quality space
segment
Operate and
exploit mission in-
orbit
Space and
Ground Segment
disposal
IOQR IOORs MCOR
Operations
100 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
GS preparation process
101 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
BIBLIOGRAPHY
102 Taller de Diseño de Picosatélites (CUBESATS) y Estaciones de Tierra. Ana Laverón Simavilla
Bibliography
1. Ground systems and operations – Part 1: Principles and requirements
2. Ground systems and operations – Part 2: Document requirements definition
3. James Webb Space Telescope Project. Mission Operations Concept Document
4. MSG Ground Segment Design Specification (GSDS)
5. EGOS, ESA Ground operations Software System, SpaceOps 2004, N. Peccia
6. Space mission analysis and design, J.R. Wertz and W.J. Larson
7. Spacecraft systems engineering, P. Fortescue and J. Stark